``Horizontal'' Grover's Search Algorithm

概要：
Quantum computation is a novel computing paradigm which is based on
the quantum mechanics. One of the striking quantum algorithms is
Grover's search algorithm. With a classical algorithm, we need $O(N)$
operations to find an element out of an unsorted data array of size
$N$. Grover's search algorithm, in contrast, provides more efficient
solution which needs only $O(\sqrt{N})$ operations by using power of
quantum computer. Grover's algorithm is extended for finding an
ordered $m$-tuple in the unsorted data arrays of size $N$ in
$O(\sqrt{N})$ steps, where $m